1. Field of the Invention
The present invention relates to a probing device, and more particularly, to an active probe card capable of improving the testing bandwidth of a device under test (DUT).
2. Description of the Prior Art
Generally, after wafer fabrication is completed, a wafer will go through a testing flow to determine whether the semiconductor device is able to operate normally. In the testing flow, a probe card, a prober, and a tester work together to test electrical characteristics of chips on the wafer. The probe card includes a printed circuit board (PCB) mounted with several fine needles, which serves as a testing interface between the prober and the semiconductor device under test. The prober is responsible for precisely moving a piece of wafer to a right position where the probe needles of the probe card are able to probe and contact the corresponding pads in a chip. The tester is responsible for sending out testing signals via the probe card to test or measure the parameters, functionalities, and electrical characteristics of the semiconductor device.
With the advancement of wafer-level packages, high frequency circuits, and three-dimensional integrated circuits (3D IC), high speed or radio frequency (RF) testing is needed for wafer probing or chip probing (CP). For a high speed circuit test, however, the probe needles are equivalent to parasitic inductance. In addition, the high speed testing signals need to go through a relatively long trace from the probe card PCB to the semiconductor device under test. As the high speed testing signals reach the semiconductor device under test, the signals may have already degraded significantly.
Moreover, many semiconductor devices are designed for low power operations in order to meet the demand for energy-efficient electronic products. Nevertheless, such semiconductor devices usually have less driving capability so that signals sent out from the semiconductor device under test will be full of jitter noise after passing through the probe needles and the probe card PCB. In this situation, the tester may not be able to obtain accurate testing results. Consequently, the testing bandwidth is narrowed.
Therefore, it is a challenging task to improve the testing bandwidth of the semiconductor device under test so as to overcome the issues of high speed circuit testing as mentioned above.